Stat Question 2

#1
The cost of college education has increased at a much faster rate than costs in general over the past 20 years. In order to compensate for this, many students work part or full time in addition to attending classes. At one university, it is believed that the average hours students work per week exceeds 20. To test this at a significant level of 0.05, a random sample of n = 20 students was selected and the following values were observed.
26 15 10 40
10 20 30 36
40 0 5 10
20 32 16 12
40 36 10 0

Based on these sample data, the critical value expressed in hours:
a. is approximately equal to 25.26 hours
b. is approximately equal to 25.0 hours
c. cannot be determined without knowing the population standard deviation.
d. None of the above.